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The Effect on Room Acoustical Parameters Using a Combination of Absorbers and Diffusers : An Experimental Study in a Classroom

Arvidsson, Emma LU ; Bard, Delphine LU ; Nilsson, Erling LU and Karlsson, Ola (2020) In Acoustics 2(3).
Abstract (Swedish)
Several room acoustic parameters have to be considered in ordinary public rooms, such as offices and classrooms, in order to present the actual conditions, thus increasing demands on the acoustic treatment. The most common acoustical treatment in ordinary rooms is a suspended absorbent ceiling. Due to the non-uniform distribution of the absorbent material, the classical diffuse field assumption is not fulfilled in such cases. Further, the sound scattering effect of non-absorbing objects such as furniture are considerable in these types of rooms. Even the directional characteristic of the sound scattering objects are of importance. The sound decay curve in rooms with absorbent ceilings often demonstrate a double slope. Thus, it is not... (More)
Several room acoustic parameters have to be considered in ordinary public rooms, such as offices and classrooms, in order to present the actual conditions, thus increasing demands on the acoustic treatment. The most common acoustical treatment in ordinary rooms is a suspended absorbent ceiling. Due to the non-uniform distribution of the absorbent material, the classical diffuse field assumption is not fulfilled in such cases. Further, the sound scattering effect of non-absorbing objects such as furniture are considerable in these types of rooms. Even the directional characteristic of the sound scattering objects are of importance. The sound decay curve in rooms with absorbent ceilings often demonstrate a double slope. Thus, it is not possible to use reverberation time as room parameter as a representative standalone acoustic measure. An evaluation that captures the true room acoustical conditions therefore needs supplementary parameters. The aim of this experimental study is to show how various acoustical treatments affect reverberation time T20, speech clarity C50 and sound strength G. The experiment was performed in a mock-up of a classroom. The results demonstrated how absorbers, diffusers and scattering objects influence room acoustical parameters. It is shown that to some extent the parameters can be adjusted individually by using different treatments or combination of treatments. This allows for the fine-tuning of the acoustical conditions, in order to fulfill the requirements for achieving a high-quality sound environment. (Less)
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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Acoustics
volume
2
issue
3
pages
19 pages
publisher
MDPI AG
external identifiers
  • scopus:85101314767
ISSN
2624-599X
DOI
10.3390/acoustics2030027
language
Swedish
LU publication?
yes
id
d1c3aadb-d98e-4893-86bf-0fd9626141b6
date added to LUP
2022-04-19 20:45:59
date last changed
2022-07-13 04:04:25
@article{d1c3aadb-d98e-4893-86bf-0fd9626141b6,
  abstract     = {{Several room acoustic parameters have to be considered in ordinary public rooms, such as offices and classrooms, in order to present the actual conditions, thus increasing demands on the acoustic treatment. The most common acoustical treatment in ordinary rooms is a suspended absorbent ceiling. Due to the non-uniform distribution of the absorbent material, the classical diffuse field assumption is not fulfilled in such cases. Further, the sound scattering effect of non-absorbing objects such as furniture are considerable in these types of rooms. Even the directional characteristic of the sound scattering objects are of importance. The sound decay curve in rooms with absorbent ceilings often demonstrate a double slope. Thus, it is not possible to use reverberation time as room parameter as a representative standalone acoustic measure. An evaluation that captures the true room acoustical conditions therefore needs supplementary parameters. The aim of this experimental study is to show how various acoustical treatments affect reverberation time T20, speech clarity C50 and sound strength G. The experiment was performed in a mock-up of a classroom. The results demonstrated how absorbers, diffusers and scattering objects influence room acoustical parameters. It is shown that to some extent the parameters can be adjusted individually by using different treatments or combination of treatments. This allows for the fine-tuning of the acoustical conditions, in order to fulfill the requirements for achieving a high-quality sound environment.}},
  author       = {{Arvidsson, Emma and Bard, Delphine and Nilsson, Erling and Karlsson, Ola}},
  issn         = {{2624-599X}},
  language     = {{swe}},
  month        = {{07}},
  number       = {{3}},
  publisher    = {{MDPI AG}},
  series       = {{Acoustics}},
  title        = {{The Effect on Room Acoustical Parameters Using a Combination of Absorbers and Diffusers : An Experimental Study in a Classroom}},
  url          = {{http://dx.doi.org/10.3390/acoustics2030027}},
  doi          = {{10.3390/acoustics2030027}},
  volume       = {{2}},
  year         = {{2020}},
}